<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>新增长度单位</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .box1 {
            width: 200px;
            height: 200px;
            background-color: deepskyblue;
        }
        .box2 {
            width: 20vw;
            height: 20vh;
            background-color: green;
        }
        .box3 {
            width: 20vmax;
            height: 20vmin;
            background-color: orange;
        }
    </style>
</head>
<body>
    <div class="box1">像素</div>
    <div class="box2">vw和vh</div>
    <div class="box3">vmax</div>
</body>
</html>